The chemical nature of the conjugated forms of prostaglandin found in human urine and of adducts formed from PGA1 by passage through dog kidney will be determined. The levels of this substance(s) in urine will be assessed by radioimmunoassay of the PGB2 liberated by treatment with KOH. Levels in normal human female urine will be established and compared with levels in pathological states thought to affect prostaglandin production, e.g., renal artery stenosis, essential hypertension, and malignant tumors. The natural occurrence of pola conjugates of PG in urine raises the question of the ability of kidney to generate PGA. The ability of kidney of various species incuding human to convert PGE1 to PGA1 will be assessed, using assays for PGA1 in the conjugated and unconjugated forms. Bradykinin is known to be a potent stimulator of prostaglandin synthesis in mammalian kidney and in vascular endothelium. It has been suggested that bradykinin acts to stimulate an endogenous lipase which liberates the unsaturated fatty acid precursors of prostaglandins. Experiments to test this hypothesis will be performed, using homogenates of rabbit renal medulla. The effect of bradykinin on unsaturated fatty acid release and on the generation of possible mediators of hormone action, such as cAMP and cGMP will measured. If preliminary experiments are successful, the characterization of the renal hormone-sensitive lipase will be undertaken.